Method of stretching wire ropes



March 20, 1934. (5. mp 1,951,687

METHOD OF STRETCHING WIRE ROPES Filed Oct'. 13, 1930 F a W Patented Mar. 20, 1934 METHOD OF STRETCHING WIRE ROPES Georg Zapf, Cologne, Germany, assignor to Felten & Guilleaume Carlswerlr Actien-Gesellschaft, Cologne-Mulheim, Germany Application October 13, 1930, Serial No. 488,463

Germany October 17, 1929 2 Claims.

'In my U. S. Patent No. 1,822,189, issuedSept. 8, 1931, I have described a method of reducing the extension of vwire ropes, more particularly ropes employed in the erection of bridges, under 5 the load to which they are subjected after erection, said method consisting in stretching the wire ropes by applying forces to subject the ropes to tensile stresses and tightly wrapping the ropes while in the stretched state with a helical wire bandage before applying the rope to the purpose for which it is intended.

The present invention has for its object to enable the stretching of the wire ropes to be effected in cases in which owing to lack of space, the rope gfinot be stretched over its entire length at one In accordance with the present invention, the stretching is effected by securing clamps to the ends of successive individual-sections of the rope and stretching each section successively by applying tensional forces to'the said clamps. The clamps are pushed over the rope and are pressed firmly Oh to theloll by means of tnreaaed nuts;

After the tensionalforces are caused to act on these clamps, that is after each stretching operation, the clamps are pushed along to the ends of the next section of the rope to be stretched. The clamps must be constructed in such a manner that they can adaptthemselves to a reduction in the diameter of the rope when the latter is stretched. without becoming loose. Examples of such clamps are shown in Figs. 1-4 of the accompanying drawing.

Fig. 1 shows a side view partly in section of a a5 constructional form of clamp and Fig. 2 is a plan view,

Fig. 3 shows a side view, partly in section of a second constructional form of clamp and Fig. 4 is a plan view. 40 Fig. 5 shows a longitudinal view of a portion of .a wire rope with clamps thereon to illustrate thev stretching of a wire rope by the method according to the invention The clamp shown in Figs. 1 .and 2 comprises a slotted, externally conical sleeve 2 having an external screw thread and a nut 3 which is screwed over the sleeve 2. The clamp is slipped over the rope 1 and the tension forces for stretching therope act on a flange-like run 4 with which 60 the nut 3' is provided.

The constructional form of clamp shown in Figs. 3 and 4 comprises an externally conical (Cl. 11'l-16) of a nut 7. During the stretching of the rope I, the tension forces act on the flange-like rim 8 of the sleeve 6. This clamp, owing to the portion thereof which is placed directly on the rope being constructed as a two-part conical sleeve 5. has the property of accommodatingitself to the reduction in diameter of the rope during the stretching to a. particularly advantageous degree.

In the case of wire ropes stretched in sections in accordance with the present invention, the

separate sections may be wrapped in a known left-hand half of the'rope has been stretched unv der" the action of these forces a bandage is applied thereto while the rope is still under the action of the said tensile forces. The clamps 9 and g0 10 at the ends of the left-hand half of the rope are then removed and applied to the ends of the right-hand half of the rope, which is then treated in the same way as the left hand half of the rope.

In this state the rope is erected in its working 35 position and subjected to the working load. after which the bandages may be removed without further extension of the rope taking place under the action of the working load.

What I claim is:

1. A method of reducing the extension of wire ropes under their working loads, by stretching the finished-wire rope, before being applied to the particular work for which it is to be used,consisting in applying clamps to the ends of successive 05 individual sections of the rope and stretching each section successively by applying tensional forces to the saidclamps.

2. A method of reducing the extension of wire ropes under their working loads, by stretching l00 the finished wire rope. before beingapplied to the particular work for which it is to be used, consisting in applying clamps to the ends of successive individual sections of the rope, stretching each section successively by applyin tensional forces to the said clamps and tightly wrapping the individual sections while subjected to the ction of said tensile forces with a helical m tal wire bandage.

G. ZAPF. 

